System of electrical distribution.



SYSTEM OP ELECTRICAL DISTRIBUTION.

APPLICATION FILED APR.20, 1909.

Patented July 28, 1914.

aMm, a (a SMM WOW:

T'Ml NOIIIS PETEIS CO. FHOTCLLITHDA, WASHINGTON. D. C

UNITED sTATEs PATENT oEEioE.

JOSEPH LESTER WGODBRIDGE, OF PHILADELPHIA, PENNSYLVANIA.

SYSTEM OF ELECTRICAL DISTRIBUTION.

To all 'whom it may concern.'

Be it known that I,JosEPH LESTER VooD- BRIDGE, a citizen of the United States, and a resident of Philadelphia, in the county of Philadelphia and Sta-te of Pennsylvania, have invented a certain new and useful System of Electrical Distribution, of which the following is a specification.

My invention relates to systems of distribution in which a source of `alternating current is supplying a fluctuating load and more yparticularly where a source of polyphasecurrents is supplying a fluctuating single phase load, and in which a storage battery is employed for controlling the Huctuations of load on the source.

The objects of my invention are to provide simple and efficient means for causing the storagev battery to relieve the generating source of the load fluctuations and, if the source is polyphase andy the load single phase, to provide a uniform distribution of theload over the several phases. One of the pieces of apparatus described herein for accomplishing the desired results is a constant current single phase alternator, which in itselfis novel. These and other objects, as well as the general nature and characteristic features of the invention, will be more clearly understood by reference to the following description taken in connection with the accompanying drawing.

The view shown in the drawings is diagrammatic and illustrates one embodiment of the invention.

In the drawings A is a source of alternating current supplying the load L1, L2; B is aregulating battery and Gr is a transforming apparatus for transferring energy between the battery and the load circuits; R is a rectifying device for transforming alternating current from the load circuit into direct current for controlling the elds of the machines I1, I2.

I1, I2 are constant current Aalternators which deliver current to the primary windings of the transformers T3,T1, respectively,

thereby controlling the current in the secondary windings of these transformers to effect the desired regulation between the battery and the circuit through the apparatus G.

A, represents a three phase alternating current generator connected in the well known manner to the primary terminals of the three-phase-two phase-transformer T1,

Specification of Letters Patent.

l App1icaton filed April `20, 1909. Serial No. 490,988.

Patented July 28, 1914.

whose secondary terminals are connected to the co-nductors l, 2, and 3, 4 of a two-phase circuit. Across the conductors 1, 2 of one phase is connected a fluctuating single phase load L1. A constant load L2 may be connected across the conductors 3 4 of the other phase, and the loads L1 and L2 may be unequal. Connected to conductors 3, 4, and also by means of conductors 30 and 31 to conductors 1, 2, is shown a rectifying device G, to the direct currentterminals of which is connected the storage battery B. This rectifying device is similar to that described in Patent #880,705, issued to me under date of March 3rd, 1908. It consists of an annular magnetic circuit D having openings O dividing it into an outer and an inner rim. A winding 5 is wound on the inner rim and connected in the usual manner to a commutator C, only a few of the connections from the winding to the commutator being shown in Order to simplify the drawing. It Will be understood, however, that this apparatus may be constructed like an ordinary direct current armature with its commutator,with the addition of a magnetic return circuit corresponding with the outer rim above referred to,whioh is fiXed in position relatively to that portion of the magnetic circuit embraced by the winding. As here shown the magnetic circuit and the winding and commutator are fixed in position while the direct current brushes are revolved. It will be understood, however, that this arrangement may be inverted and the brushes may be stationary while the structure including the entire magnetic circuit, the winding and ccmmutator may revolve. Two pairs of direct current brushes are shown, one pair 9, l0, being short-circuited by a low resistance conductor 6, while the other pair l1, 12, is connected to the terminals of the battery B. It will be understoodthat these latter connections are made by means of collector rings on the shaft H in the usual manner, these collector rings being omitted in order to simplify the drawing. These two sets of brushes bear upon the commutator at points displaced 90 from each other and are mounted on a shaft H which is revolved by a synchronous motor M connected to the source A by conductors 25, 26, and 27. The field of the synchronous motor is shown .at F.

The alternating current terminals of the winding 5, are located at points 44, 45, 46,

and 17, lspaced 90 apart, these points being connected to the two-phase circuit as noted above. Two transformers T3', T45, are shown,

one in each phase, the secondaryrwinding of T3 being connected in series with conductor .30, and the secondary. winding of TJA beingY the primary :windings of'T3 and T4, respec-l tively, alternatingl current-s which may be held constant 'at any. predetermined value or may llbe caused to fluctuate withy fiuctuations of loadonfthecircuit 1,' 2,v as will be' de'- scribed herein below. The effect of these currents inthe 'primarywindings oi'tians'- fo'rm'ersf-Ia and'T- will-'betodetermine the transfer ofA energy 'betwee'nlthe v source `A and the battery through the rectifying apparatus G, as' well as the distribution of this Senergy betweenthe circuits l,-2,and3, 4. For any tendency to aflow of currentfthrou'gh#:the secondaries off-thetransformers :T3l and T other thanthalt correspondingto the current in the primaries, .the'se transformers Will-"act `as choke"coilsfopposing said flow'. Assuming'first that the i load at vL1- is constant,lif' the current rfiow"'cl nived fromjil and It' in the primaries of transformers' T3 and T* be maintained constant, the 'transfer of'energy yfrom the "source A to the battery will remain' constant-L If lthe load atfL1 should increase andthe current 'inthe primary of'rtransforrner T3 'shouldbe made 'to decrease at the sametime by acorrespondL ing amountthe transfer 'of energy 'from phaser-corresponding toftheconductors l, 2, to the' zrectiirying vdevice G may be reduced by an amount equal'- to the increase-*of load at LH and the 'total transfer' of* energy from transformer T1 tothe circuit' 1, 2, may -be heldconstant1` This result is accomplished by meansiof thev rectifier R, as will be ex-I` plained below;

The machines-TL and 'I2 areidentical exceptfiiasjto the-:location of thealternating current taps tothe armature winding; The machine'i1 will-therefore now be described; It ifconsists of a field frame designed in the usual manner with four internally projecting poles and abi-polar -wound'armature' on the-shaft' H and istherefore driven by the mdtor'M" in synchronism'with the source' A.

The'armatur'e'is provided with single phase alternating ,current taps at points' 34 landv 35, whichiare connected to `the primary winding oftransformer T3 bvme`ansl of conductors Sti-and 37. It will?befunderstoodthat these connections aremade by means of the usual collectorl rings' onlthe shaft, thesel 'ringsfbeing omitted from the drawing for simplicity; Al field Winding..21 is shown fon the poles" 'of this machine connectedaeross the circuit 28,

short-circuited by conductor 48.

29, which is supplied with direct current by the exciter E. The Winding .21 is so designed that the current transmitted through it from the circuit 28, 29, will produce a bipolar field in the direction of the arrow J1. The brushes 32 and 33 bear upon. the commutator at points of maximum potential due to the field J1 and these brushes are The flow of current through conductory 48 will produce a secondary' iieldat right angles to J1 and 4this field will yproducethe voltage necessary totransmit single phase current by Iwayof conductors, 37, throughthe primarywin'ding of 'transformer T3. This flow lof vcurrent in the armature Winding of the machine I1 will produce a single phase magneto motiveA force in that armature, whichmay .be dividedinto two components rotating `aboutthe armature in opposite directions. The synchronous: rotation off the 'armature'will hold one of these components stationary in space and the value of the 'single phasecurrent output from the points`34, 35, will be such that this stationarycomponentof the magneto motive forceiwillbe I sufficient .nearly to counter balance that of the'iieldlfwindingl, leaving a 'residunm just suiiici'ent to produce the flowA of current across the-brushes 432 and 33 necessary to maintainthefrequired strength of secondary field 'above referred to.` Owing to the low resistance ofy conductor." 48 "f this residuum will belverysmalland the flow ofosingle phase currentl-from-the taps 34 and will be practically proportional to the excitation produced by the'fieldwinding 21, andI so longlas'v this excitation'is constant the output of single phase current from the points 84and'85 -tothe primary Winding of transformer T3 will 'be4 constant.l The second component of the single phase magneto m'otive forcefwill by reason of the rotation of the armature be revolved fin` space at a speed double that of synchron-ism; In order to neutralize 'the effect of this componenty a conducting squirrel cage structurev U1 is shownl surrounding the armature in' close proximity to its periphery. The method of constructingthis" squirrel cage is Well known in the art and need not beI further described here. The" currents induced yin this squirrel cage as a result ofv thesecond componentofl the `single Aphase magneto motive 'force' will besuch as tio-practically neutralize 'this component leaving merely ythe small"residuum-necessary to produce these induced currents. The machine I1 is therefore adynamo designed to-give aconstant current single phasef'output-ror broadly a single phase output proportional toits fdi rect.' current field excitation.

ThefvmachinefP as mentioned above,is identicalvwith I?, except that the single phasetaps 40, 41 'aredisplaced 90- from the position of the taps 34, 35, in machine Il. The single phase output from the machine I2 will therefore be displaced in phase 90O from the output of the machine 11. On the machine Il is shown a second field winding 22 and on `machine I2 is shown a second field winding 23. These two field windings are connected in series `with each other across the brushes 15, 16, of the single phase rectifier R. This rectifier is similar to that described in my Patent No. 941,599, issued November 30th, 1909. It consists of a stationary magnetic circuit 19, provided with a conducting vsquirrel cage 20, within which is rotated an armature X provided with a commutator Y upon which bear two sets of brushes 13, 14 and 15, 16, respectively. Brushes 13, 14, are short-circuited while brushes 15, 1G, are connected to the field windingsj22 and 23, as mentioned above. Single phase taps are taken from the armature at 'points 17 and 1S and are connected to the terminals of the secondary winding of transformer T2 whose primary is conn nected into conductor 1, so as to carry the total demand of the load L1. A multiple Contact switch Z is shown for adjusting the number ofturns of the secondary winding of transformer T2, which may be in circuit at any time, thereby adjusting the ratio of transformation. The armature X is mounted on the shaft H and rotated by the motor M in synchronism with the source A. The flow, of single phase current from transformer T2 through the armature Xwill` produce a single phase alternating field in this armature and in the magnetic circuit sur@ rounding it which may be divided into two components rotatingin opposite directions. One of these will beheld stationary in space by the rotation of the armature and is represented by an arrow S. It will produce a direct current electro-motive-force across the brushes 13, 14, and a flow of current through the conductor 50, thereby producing a secondary field at right angles to the field S. This will produce an electro-motiveforce, across the brushes 15, 16, of sufficient amount to cause a fiow of current from these brushes through the eld windings 22 and 23, sufficient to nearly neutralize the magneto motive force due to the flow of single phase current from transformer T2, leaving` only a small residuum necessary to produce the field S and the flow of current in the conductor 49. The second component of the alternating field produced by the current from transformer T2 will rotate in the direction of the armature rotation but at double frequency and will be practically neutralized by the squirrel cage structure 20 in the same manner as described in connection with the machine 11. The flow of direct current from the machine R, through the field windings 22 and 23, will therefore be proportional to the single phase alternating current demanded by the load L1. A1 resistance K3 is shown connected in parallel with field winding 23 which may be used to adjust the proportion of current flowing.

through this field windingas compared with that in winding 22. The effect of current in the field winding 22 of the machine 11 will therefore be proportional to theload L1 and the winding 22 may be so connected as to oppose winding 21 which receives a constant current from the exciter E. An increase of load atL1 will therefore reduce the total magneto motive force of the field windings on machine Il and correspondingly reduce the output of alternating current to the primary winding of transformer T3, thereby reducing the amount of` energy transmitted from conductors 1 2, through the machine G to the battery. The apparatus may be so proportioned that this reduction in the amount of energy transmitted to the battery will equal the increase of load at L1 and therefore the total energy taken from the circuit 1 2 will remain constant.` 1f the increase of load at L1 is sufficiently great the transfer of energy from the circuit 1 2 to the battery may be reduced to zero or may even be reversed causing the battery to discharge through the rectifying apparatus Gr into the circuit 1--2 to assist in carrying a portion of the load L1. If the resistance is all cut out of rheostat Kg so that the field winding 23 on machine 12 is short-circuited, variations of load at L1 will not affect the alternating current output of machine 12, and the vamount of energy transmitted to the battery by way of conducto-rs 3 4, will remain constant. Under these conditions the total' load on the source will remain constant regardless of fluctuations of load at L1.

By the proper adjustment of the rheostats K1 and K2 the alternating current outputs of the two machines 11 and 12 may be made equal when there is no load at L. This would produce an equal distribution of load between the two phases of the two-phase circuit 1 2 and 3 4, and will therefore, equalize the loads on the three-phases of the source A. This adjustment having once been made, will remain regardless of fluctuations of load at L1. It may, however, be desirable to permit the source A to take a certain proportion of the load fluctuations while still dividing these fluctuations equally between the different phases. This could be accomplished by a suitable adjustment of the switch Z and of the rheostat K3. By cutting in additional turns of the secondary winding of the transformer T2 by means of switch Z, the flow of alternating current into the rectifier B for a given load at L1 may be reduced. This will reduce the effect of the field winding 22 and the variations of current from the machine Pf through the primary', winding of the transformer T3, by their efl'ect'on the transfer of energy between the circuit 1-2 and the battery, willionly partially compensate for the. fluctuations of load at L1, and a portion of these fluctuations will fall on the transformer T1'.` By cutting in a part of the resistanceofy the'rheostat K3, the effect of load fluctuations at L1 will be felt in the field winding l23 of the machine I2. This winding may beso connected as to assist winding 24 which is suppliedhwith constant current from the exciter E, so that an increase of load at LV1 will cause=an increaseof current in the primarywinding of transformer T* and therefore-an increase ofv load on the -other phase 4of the transformer T1. If this latter increase 'of load is made, by a suitable adjustment of the rheostat K3, equal to the increase of load .falling upon the transformer TI from the circuit 1-2, then the fluctuations' of load will be equally divided between the ltwo-phases of the two-phase circuit and will therefore be equally distributed over the three yphases of the source A.

It will be understood that the phase relations of the currents transmitted by the machines l'l1-and I2 through the. primary windings/of transformers T3 and T4 may be adjusted in any one of several different ways, as for example, by a suitable location of the taps-34,35, 40 and-41, or by a proper adjustment ofthe armatures Q1 and Q2 on the shaft H, or by'V a proper adjustment of the field frames of these-two machines. Ordinarily these adjustments -would be made-so as to bring ythe-current transmitted through the primary'Wi-ndings of transformers T3 and T into phase with the potential across conductors 1, 2, and 3, 4, respectively. Circumstancesmight arise in which it would be desirable that these currents should be more or 'less out of phase, as for example, to compensa-te for a wattless component of the load L1, and such adjustment could readily be effected.

The rectifying apparatus G is not dependent upon exciting current Afrom the alternating current circuit 'to maintain the required rotating magnetic field. This field is produced by a flow of current through the winding 5, the brushes 9 and 10, and the conductor 6, in the following manner: A small flow of current fromf-the battery through the brushes 11 and 12 and the winding 5 will produce a small magnetic flux in a direction corresponding with the line of contact yof brushes 11 and 12,v which will revolve with these brushes. This will produce a small electro-motive-force between the brushes 9 and 10 and a flow of current through conductorf 6. On account of the low resistance of this latter conductor a small electro-motive-force will produce a considerable flow of current land the effect of this current vin thewinding 5 will be to'produce a-.second field at right angles to the first and of considerable magnitude, suflicient in fact to produce a counter Ielectro-motive-force across the brushes 11 and 12 .nearly equal tothe potential applied to these brushes by the battery. The excess of battery potential will be ljustsuflicien-t to permit the `small flow of current through the winding 5 yby way of brushes 11 and 12 above mentioned. It will be seen therefore that the potential induced in the winding 5 by the second field above referred to will be dependent upon the `potential maintained by the battery across the brushes 11 and 12. This characteristic is important since the self induction in the transformers T3 and T 4 would prevent a flow of magnetizing current through the winding 5 lfrom the alternating current circuit, and if the counter electro-motive-foroe at the brushes 11 and 12 were not maintained by means of the other pair of short-circuited brushes as above described the winding 5 being of low vresistance would constitute a short-circuit for the battery and the apparatus would be inoperative. Whenever alternating currents are taken out or sent into the winding -by means of conductors 3 4 and 30'-31 the effect of these will be to cause a corresponding flow of current 'out 95 of or into the battery by way of the brushes 11 and 12; these currents being so combined in the ywinding 5 that the resultant magneto motive-force will be equivalent to that of the small flow of current frstfmentioned from 10) the battery by way of brushes 11 and 12. Briefly the combination shown-comprises a polyphase source supplying a load which is unequally distributed over the several phases, and provides means for taking en- 10 ergy from a lightly loaded phase, storing said energy in a storage battery during a portion of each cycle, and deliveringsaid energyto a more heavily loaded phase during the remainder of the cycle, thus equalizing the load on the several phases, and at the same time it may compensate for fluctuations of load on one or more of the phases.

Switches W1 and W2 are shown connected respectively across the conductors 36-37 115 and 38-39. If these switches-are closed the primaries of transformers T3 and T are short-c-ircuited, and these transformers will have no effect in controlling the transmission of energy between the circuit 1-2 and 120 the rectifying apparatus G.

The machines Il and I2, as noted above, may be used asconstant current single phase alternators, or may be used to give a single phase output whose current value is dependent upon the field excitation of the machine and practically independent of any resistance or counter' electro-motive-force in the external circuit. It will be understood that a machine of this kind may be applied to U9 many uses other than that shown and described herein, and the control of its field excitation and therefore. of its current output may be effected in any of the many ways well known in the art. I have therefore directed certain claims to this machine taken by itself and have embodied said claims in a divisional application, Serial No. 562,355 filed May 20, 1910.

What I claim is:

1. In combination, a poly-phase source, a

load unequally d istributed between the phases, a storage battery, and means for taking energy from a lightly loaded phase, storing said energy in the battery during a portion of each cycle 'and delivering said energy to a more heavily loaded phase during theremainder of each cycle. 2. 'In combination a poly-phase source, a single phase work circuit supplying a fiuctuating loadv connected to one phase of the source,`a storage battery, rectifying apparatus connected between the battery and all phases of the source, and adapted to receive a constant amount of energy from the phases other'than the working phase and to transmit energy to or from the working phase varying with the iiuctuations of load thereon, and to transmit the surplus to or from the battery to maintain constant load equally distributed on all phases off the source.

3. An alternating current source and its circuit, a fluctuating load supplied thereby, a storage battery a magnetic circuit all parts of which are relatively fixed, a winding on said `magnetic circuit, a commutator connected to said winding, two sets of relatively displaced brushes bearing upon said commutator whereof one set is connected to the storage battery while the brushes of the other set are interconnected by a separate conducting circuit, means for producing relative rotation'of brushes and commutator in synchronism with the source, appropriate connections from the Winding to the alternating current circuit, a plurality of coils in inductive relation, whereof some are connected in series between the winding and the circuit, and means for transmitting through the others alternating currents of predetermined value in synchronism with the source.

4. An alternating current source and its circuit, a fluctuating load supplied thereby, a storage battery, a magnetic circuit all parts of which are relatively fixed, a winding on said magnetic circuit, a commutator connected to said winding, two sets of relatively displaced brushes bearing upon said commutator whereof one set is connected to the storage battery while the brushes of the other set are interconnected by a separate conducting circuit, means for producing relative rotation of brushesl and commutator in synchronism with the source, appropriate connections from the Winding to the alternating current circuit, a plurality of coils in inductive relation, whereof some are connected in series between the winding and the circuit, means for transmitting through the others alternating currents in synchronism with the sourse, and means independent of the load for controlling said currents.

5. An alternating current source, and its circuit, a fluctuating load supplied thereby, a storage battery a magnetic circuit all parts of which are relatively fixed, a winding on said magnetic circuit, a commutator connected to said winding, two sets of relatively displaced brushes bearing upon said commutator whereof oneset is connected to the storage battery while the brushes of the other set are interconnected by a separate conducting circuit, means for producing relative rotation of brushes and commutator in synchronism with the source, appropriate connections from the winding to the alternating current circuit, a plurality of coils in inductive' relation, whereof some are connected in series between the winding and the circuit, means for transmitting through the others alternating currents in synchronism with the source, and two means for controlling said currents whereof one is independent of the load and the other is responsive thereto.-

G, A poly-phase alternating current source and its circuit, a fluctuating load supplied by one phase of said source, a storage battery, a magnetic circuit all parts of which are relatively fixed, a winding on said magnetic circuit, a commutator connected to said winding, two sets of relatively displaced brushes bearing upon said commutator whereof one set is connected to the storage battery, a separate conducting circuit interconnecting the brushes of the other set, means for producing relative rotation of brushes and commutator in synchronism with the source, appropriate connections from the winding to the several phases of the alternating current circuit, a plurality of current transformers, one for each phase, having their secondary coils connected in series between the said winding and the alternating current circuit, means for transmitting through their primary coils alternating currents in synchronism With the source, means independent of the fluctuating load for controlling said alternating currents, and means responsive to the fluctuating load for controlling the alternating current in the primary of the current transformer connected to the loaded phase.

7 In combination a polyphase alternating current circuit and its source, translating devices constituting an unbalanced'load Whereof that portion on one of the phases is fluctuating, a storage battery, means for transferring energy in either direction between the battery-fand the circuit,:meansre` sponsive to the fluctuating Aload and adapted to control the-transfer of energy between the battery andthepli-ase carryingsaidfiuctuatingv load,` Yand other 'means for vcontrolling the transfer vof energy between the battery and the vother phase or phases.

In combination, a polyphase alternating current circuit and its source, translating-devices constituting a load connected to the circuit rand unbalanced in'respect to the phasesthereof, a. storage battery,meansfor transferring energy between the battery and the circuit,A and means `for-controlling the distribution otv said energy between the battery and the several phases.

m9. In combination, a polyphase4 alternating current circuit and its source, translating -V devices lcornstituting a Hu'ctuatingl load connected to'one phase offthe circuit, storage apparatus, means for' transmitting :energy 1n `either. direction l between Asaid Iapparatus `and the circuit, and means vresponsive to the fiuctuati'ng `load andy `adapted to `control 'the transmission of energybetween said apparatus `andthe several phasesof the circuit whereby a. 'portion-of each lload fiuctuationfisplaced upon-the battery and/the balance is divided with substantial equalitybetween the-phases l0. In combination a polyphase alternating current circuit'L and its source, `translating'de'vices constituting a load unbalanced between :the phases, transforming apparatus interconnected between the phases and adapted to transfer energy between them, and-means for introducing alternating E. M F; between the transforming apparatus and the circuit, said E. M. F. controlled by current in said circuit andadapted to 0011- trol said'transfer of energy between'the phases.

11. In combination, a polyphase altenuting current circuit and its source, translab ingdevices constituting avfluctuating load connected to one phase of the circuit, lstorage apparatus, converting apparatus-oon nected between the storage apparatus und the circuit, means responsive t0 uctuatiins of load-on said one phase `andt adpaptedtO cause energy to be transmitted through the converting apparatus between said;

l and the storage apparatus, and other meins for causing energy to` be .transmitted between the other phase or phases and the storage apparatus.

In testimony 'whereof Imhave hereunto signed my name.

"NBEPH LESTER WMDBRIDGB. lllitliesses:

CLIFFORD K. Cassin, FRANK? E. FRENCH.

'hli pllllil'y b. dbthled-fox' ive dents Inch, 4'by' aldrlinf the "-Cdlllllmtvfofhm,

Washington, D. C. 

